integer-expression
The number of seconds to be added to the time-or-timestamp-expression. If integer-expression is negative, the appropriate number of seconds is subtracted from time-or-timestamp-expression. If you supply an integer expression, the time-or-timestamp-expression must be explicitly cast as a TIME, DATE, or TIMESTAMP data type. If time-or-timestamp-expression is a DATE type, its time portion is assumed to be midnight.

Syntax 1
If you pass a single timestamp-expression to the SECONDS function, it will return the number of seconds between midnight 0000-02-29 and timestamp-expression as an UNSIGNED BIGINT.

Note

0000-02 is not meant to imply an actual date; it is the default date used by the SECONDS function.

Syntax 2
If you pass two TIMESTAMP values to the SECONDS function, the function returns the integer number of seconds between
them as a SIGNED BIGINT value.

Syntax 3
If you pass a TIMESTAMP value and a INTEGER value to the SECONDS function, the function returns the TIMESTAMP result
of adding the integer number of seconds to time-or-timestamp-expression. Similarly, if you pass a TIME value to the SECONDS function, the function returns a value of type TIME.

Instead of Syntax 2, use the DATEDIFF function. Instead of Syntax 3, use the DATEADD function.